Missions

Photoinhibition is a process where light irreversibly damages Photosystem II, the crucial photosynthetic enzyme allowing water oxidation. The initial mechanism of the process is under debate, and the exact location of the damage site(s) is unknown. During the project, we aim to understand the molecular details of photodamage from a number of perspectives: as a function of the light color and intensity, using physiological, structural, and biochemical tools.
To understand the molecular details of photoinhibition, in particular the energy dissipation process occurring upon damage (1), potential role of cytochrome b559 in photoprotection, and locating the side of the initial damage, you will work with internal- and external collaborators. You will be primarily tasked with development of genetic and biochemical tools in Chlamydomonas reinhardtii and Thermosynechococcus vulcanus, with freedom to explore the nature of energy conversion in these species using functional approaches.
(1) Nawrocki, W. J., Liu, X., Raber, B., Hu, C., De Vitry, C., Bennett, D. I., & Croce, R. (2021). Molecular origins of induction and loss of photoinhibition-related energy dissipation qI. Science advances, 7(52), eabj0055. doi.org/10.1126/sciadv.abj0055

Activités

- The candidate will develop tools for random mutagenesis of the chloroplast genome of chlamydomonas (including conceptualisation, execution, and troubleshooting of all aspects of the project; this work will be partly done with other geneticists in the hosting laboratory and with external collaborators)
- Culturing, scale-up, and development of purification techniques of membrane proteins from thermophilic cyanobacteria using standard, readily-available protocols. Characterisation of the preparations using basic spectroscopic and biochemical methods.
- Functional measurements of photosynthesis in vivo and in vitro using spectroscopic techniques (no prior experience is required, and training will be provided)

Compétences

Broad experience in at least two of the following techniques is expected:
- microbiology techniques, culture scale-up, bioreactors use
- (membrane) protein solubilisation and purification using preparative chromatographic techniques or differential centrifugation
- generation of mutant lines in plants of eukaryotic microorganisms, cloning, gene sequence design, random mutagenesis
- time-resolved and steady-state fluorescence and absorption spectroscopy of photosynthetic samples or organisms

Contexte de travail

The UMR 7141 « Chloroplast Biology and Light-sensing in Microalgae » laboratory is located in the heart of Paris, in the Latin Quarter, a lively district with a student environment and firm place in the history of science. Our lab is dedicated to the study of light-driven processes (photosynthesis and photoperception) and chloroplast biology. The UMR 7141 addresses key questions on the biology, evolution and ecology of microalgae by focusing on different model systems and on ecologically-relevant phytoplankton. We put emphasis on a collaborative and interdisciplinary nature of the research, and use approaches of eco-physiology, biophysics, biochemistry, genomics, and genetics. The laboratory is inclusive and strives to accommodate candidates from all backgrounds.
In particular, you will work with a range of internal- and external collaborators in order to promote a two-way knowledge transfer. These include geneticists, biochemists, structural biologists, and spectroscopists, in the hosting lab, in Paris region, and internationally.